Mobil 1 oil weight

[Al Streicher]

Ameer,
Although the bearing are new is not the point, it's the clearance between 
said bearings and the crank or camshaft. If the clearance is say.002"-.003", 
then I would say use a 30 weight oil. The viscosity needs to match the 
clearance. If the makeup is a thick oil, say 40-60 weight, you'll need more 
clearance to allow the molecules to squeeze into the gap. Plus, as mentioned 
before, what is the make up of the oil passages, narrow or wide? As the 
enigne is worn in, you might have to increase the viscosity.
I can only speak to older Chevy engines, that I have rebuilt many, they use 
very tight clearances and always recommended 10W-30. In a typical V8, most 
of the oil was pushed up to flood the valve area and the cam.

If you do not get valve noise upon startup and the oil temp is normal for 
that engine, then stay with "Dino" oil or a blend. IMHO

Al
----- Original Message ----- 
From: "Ameer Antar" <antar at comcast.net>
To: <john at westcoastgarage.net>
Cc: "Quattro List" <quattro at audifans.com>
Sent: Tuesday, May 01, 2007 5:04 AM
Subject: Re: Mobil 1 oil weight


>I agree that 0w40 is too extreme for my old car, but I was thinking of 
>sticking
> with 10w30. I based this off the fact that the S6 has a similar engine 
> design
> and has a similar oil grade chart to mine. So if A=B and B=C, then A=C, 
> right?
> Keep in mind this is a rebuilt motor, so it's not like I'm running on 22+ 
> yr
> old bearings.
>
> -Ameer
>
SNIP